DodgeTalk Forum banner
Status
Not open for further replies.

Slant Six to 318 swap?

8K views 7 replies 5 participants last post by  psm4nh3 
#1 ·
Hey guys,

I can get a 1970 318 for $100 from a friend and throw it in my 1980 Road Runner but I wanted to find out what is needed to do the swap or if I can keeping my 3-speed manual w/overdrive trans.

I know I need the 6 to V8 motor mounts and the v8 bellhousing. But will my transmission spline be the same as that on the 318? I don't know what the spline is all I know is that it is a 1980 3-speed manual w/overdrive. Would a different driveshaft be needed?

Any information on the swap would be greatly appreciated.

Thanks :gr_patrio
 
#2 ·
You'll need the Shumacher Creative Services engine swap kit that allows the V8 to bolt to the /6 K-member, www.engine-swaps.com

Of course a V8 radiator, and perhaps HD torsion bars as well. I know the F-bodies have those weird horizontal type torsion bars.

I'm not sure if the 3-speed was available behind a V8, but you might be able to go to the A-833 4-speed transmission.
 
#3 · (Edited)
Just doing some parts lookup....looks like the V8 clutch is a 10.5" 23-spline set up. Your slant six either has a 9.25" 23-spline or 10" 23-spline clutch. The splines are the same...it may work or it may not. Don't know if that 3-speed will bolt up to a V8 bellhousing. What model transmission is it?
 
#4 ·
I am thinking you have a 4spd already, so I would say mounts, bellhousing(clutch fork,clutch and pressure plate) and flywheel along with v-8 fan shroud and misc pulleys brackets(junk yard crawl).
 
#5 · (Edited)
i did that swap. except i had an auto. 79 aspen slant six to a 360/360 horse mp crate motor.(pre magnum) i used the shumacker kit. if i had it to do over again, i would use simply swap the k member. i fond out later that an m body k is the same as an f body k member. the salvage yards are full of 5th aves and diplomats grand fury's. just find one with a318/360 and there is the rest of your brackets for conversion also.using the shumacker mounts on f body requires grinding on your 6 cyl k frame which it end ever reusing with a 6 again. also an early b body 8.75 rear will drop wright in in place of the wimpy f body rear. i even used the gran fury ac compresssor because the 6 cyl ac is not the same. and they said u couldnt run ac with that huge intake. its neat to pull up to a light with that 484/284 cam with its lopy idle windows up and not sweating.
 
#6 ·
Thanks for the info guys. I think I might just stay with the six for now. I have headers and a four barrel intake for it that I will throw on soon. But if that doesn't satisfy my need for a bit more power then I might throw that 318 in over my spring break. I want to keep this car kinda calm because its for commuting to school for 80 miles a day round trip 5 days a week. The Super Coupe stays as my gas guzzling summer car :) But I just don't like having to wait to get up to speed on the highway and such.
 
#7 ·
i am not sure about standard trans swaps. i used a904 with manual reverse valv bodyand tci 3500 converter. i also found that it would have been cheaper to do the k member swap.because for me headers fitting right was an issue. ihated bending the NEW headers on the passenger side becaause they ratteled against the frame.save yourself the trouble and swap kmembers and even use the m body motor mounts as well. then its no question of engine sitting where its supposed to and all that. its all direct bolt ins.
keep us posted on how your swap goes.
 
#8 ·
What everybody else has said. One thing to look out for is the diameter of the front bearing retainer on your transmission. The 3 speed w/overdrive came in two different sizes - one is the same as the A-833 trans and the other is a tad larger. Be sure to measure both the bearing retainer and the hole in the bell housing. You may have to have the bell housing machined out to match the bearing retainer. Any reputable machine shop can handle that (cheaper than scouring for another bellhousing).

The transmission splines are the same on three speeds and four speeds. Just be sure to use the correct clutch disc and pressure plate assembly (buy them as a matched set).

Good luck with your swap! On a side note, you may want to check into purchasing a Mopar chasis book - these cover everything from trannys to rear axles to suspension.
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top